Vortec V6 Cracked Intake Manifold

[Mberglo]

I winterized my 97 Four Winns like I do every year: open block drains and pull the hoses off the front of the manifolds. So I was a bit miffed when I started the boat for the first time this year only to have chocolate milk pumping through the valve cover breathers. I shut it down immediately (never got off the trailer). I pulled the intake off to inspect the lifter valley, and found the intake itself had cracked on the bottomside. Then I noticed the drain plug on the front of the intake. I started doing Internet searches and found a few folks here discussing the same issue. Seems I should pull that plug and then lower the bow so it actually drains.

I ordered a new intake from GCIron.com: http://www.gciron.com/GM_12552422_p/gm-12552422.htm for a good bit less than I saw on ebay.

I've attached some pics of the intake.

Thanks for the assistance.

 

[jerryjerry05]

Welcome!
No pics?
Seems like the system should have drained when the plugs were removed.
You clean out the drain plugs after you removed them?
Sometimes the shale/ rust/ crud builds up behind the screw/ plug.
You undo the circ pump hose?
Aftermarket prices are way cheaper than Volvo used parts.
Does it have the drain plug on the new?

 

[Mberglo]

I guess the photo didn't upload properly. Let's try a link.

 

[Mberglo]

The front ports you see on the intake are for water. It enters the intake on one side and exits on the other side. The water fills a large cavity. In order to drain the intake, you have to tip the bow down and let the water run to the front of the intake. You can also remove the square plug on the front, but you still have to dip the bow to let it run out. Normally, we take a long drive home from the lake, with lots of opportunity to go downhill and everything drains. Last year we started keeping our boat at the lake, so it came out of the water and immediately under a carport and cover. I opened block drains and removed lower manifold hoses and considered it done. The intake didn't drain, and it froze and cracked.

Good news is that I bought a new intake, installed it, performed a few oil changes with Seafoam, and I'm back on the water. I now have a better procedure for winterizing my boat.